Metal-Oxide-Semiconductor (MOS) devices are basic building elements in integrated circuits. An existing MOS device typically has a gate and source/drain, which can be contacted with metal contact plugs that extend through dielectric layers.
Metal contact plugs are fabricated through the deposition of metal-containing materials into openings in the dielectric layers and are typically planarized using Chemical Mechanical Polishing (“CMP”) and other subsequent fine polishing steps.
The metal contact plugs can be subject to corrosion during the planarization and fine polishing steps.